It seems that DC might just have this TV superhero thing down, as Varietyreports that the much-anticipated cross-over between Arrow and The Flash dominated television ratings this week with its two-episode, two-series event. The story arc opened on Tuesday night within the show The Flash, giving that series one of the best rated episodes it has aired so far with 4.34 million viewers overall. The conclusion followed a night later, on Wednesday, with Arrow, which racked up its “second largest overall audience ever” with 3.9 million viewers. Arrow‘s figures made it the number one show among men aged 18-34.

The Flash is a spin-off from the hit show Arrow, with the character of Barry Allen – also known as The Flash – having first appeared in season 2 of that show. Grant Gustin was cast in the role of brilliant crime scene investigator who is made meta-human by a lightning strike while accidentally doused in chemicals. The spin-off was created by the same talent behind Arrow itself, and began to air in October 2014. Arrow, on the other hand, has been broadcasting since October 2012, with Stephen Amell in the role of Oliver Queen – a billionaire playboy turned archery expert and vigilante superhero who spent years stranded on a dangerous island.

With The Flash having been continually well-received since its premiere date, fans have been excitedly awaiting a crossover between the two shows that share a TV universe. They were not disappointed, with Arrow appearing on The Flash on Tuesday, and The Flash appearing on Arrow on Wednesday. The success seemed to come from each of these tonally different shows retaining its own sense of self, despite the presence of the other superhero.

With a violent clash between the two characters at the climax of Tuesday’s episode of The Flash, it seems that Stephen Amell faced some new challenges on the set of Arrow‘s spin-off show, as Grant Gustin explained to The Hollywood Reporter.

“It was funny because he had to do a lot of new things, because it was Flash stuff, essentially. He had to incorporate Flash-time into his fighting, which I do on a weekly basis. Stephen does all practical fighting; he really does all the fights. I don’t do stuff like that – it’s effects. I do some things, but mostly its camera tricks and effects.

“So Stephen had to move in slow motion and do things by himself at times [while we were filming the fight]; I had to do things by myself. When I’m shooting Flash-time… it involves a lot of complicated things you have to do on the day [of filming], and Stephen had to learn.”

Learn he did and, according to his own tweet, was satisfied with the results.

Well, we did it. We crossed the streams and everyone survived to tell the tale. Thank you all for watching.